Aneurysmal subarachnoid hemorrhage occurring during sleep: Clinical characteristics and risk factors

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is known to be triggered by several specific human activities. Sleep, by contrast, has not been considered a triggering activity for aSAH, and clinical characteristics of patients who sustain aSAH during sleep have rarely been reported in the literature.

METHODS

This is a retrospective analysis on the data acquired through a multicenter aSAH registry. Between January 2019 and December 2021, a total of 732 aSAH patients had been registered into our database. After excluding 109 patients whose activities at aSAH onset had been unidentifiable, the remaining 623 aSAH patients were dichotomized to 59 patients who sustained aSAH during sleep (Sleep group) and 564 patients who sustained aSAH during daytime activities (Awake group). Two-group comparison of demographic variables and multivariate logistic regression analysis were performed to clarify their clinical characteristics and identify potential risk factors.

RESULTS

The Sleep group exhibited significantly higher frequencies of diabetes (15.5 % vs. 6.4 %, p = 0.01) and antiplatelet use (13.8 % vs. 4.6 %, p=0.004) than the Awake group. Furthermore, multivariate logistic regression analysis showed that diabetes (OR, 3.051; 95 % CI, 1.281-7.268; p = 0.012) and antiplatelet use (OR, 3.640; 95 % CI, 1.422-9.316; p = 0.007) were correlated with aSAH occurring during sleep. There were no significant inter-group differences in the patient outcomes evaluated at discharge.

CONCLUSION

The current results indicate that risk factors may exist for aSAH occurring during sleep. Further investigations on how comorbidities such as diabetes, antiplatelet use and sleep apnea affect human hemodynamic and hemostatic parameters during sleep is warranted to better understand those relationships.

Dysregulated haemostasis in thrombo-inflammatory disease

Inflammatory disease is often associated with an increased incidence of venous thromboembolism in affected patients, although in most instances, the mechanistic basis for this increased thrombogenicity remains poorly understood. Acute infection, as exemplified by sepsis, malaria and most recently, COVID-19, drives 'immunothrombosis', where the immune defence response to capture and neutralise invading pathogens causes concurrent activation of deleterious prothrombotic cellular and biological responses. Moreover, dysregulated innate and adaptive immune responses in patients with chronic inflammatory conditions, such as inflammatory bowel disease, allergies, and neurodegenerative disorders, are now recognised to occur in parallel with activation of coagulation. In this review, we describe the detailed cellular and biochemical mechanisms that cause inflammation-driven haemostatic dysregulation, including aberrant contact pathway activation, increased tissue factor activity and release, innate immune cell activation and programmed cell death, and T cell-mediated changes in thrombus resolution. In addition, we consider how lifestyle changes increasingly associated with modern life, such as circadian rhythm disruption, chronic stress and old age, are increasingly implicated in unbalancing haemostasis. Finally, we describe the emergence of potential therapies with broad-ranging immunothrombotic functions, and how drug development in this area is challenged by our nascent understanding of the key molecular and cellular parameters that control the shared nodes of proinflammatory and procoagulant pathways. Despite the increasing recognition and understanding of the prothrombotic nature of inflammatory disease, significant challenges remain in effectively managing affected patients, and new therapeutic approaches to curtail the key pathogenic steps in immune response-driven thrombosis are urgently required.

Ticagrelor or prasugrel in patients with acute coronary syndrome with off-hour versus on-hour presentation: a subgroup analysis of the ISAR-REACT 5 trial

OBJECTIVES

To assess the efficacy and safety of ticagrelor versus prasugrel in patients with acute coronary syndrome (ACS) presenting during off- and on-hours.

BACKGROUND

The efficacy and safety of ticagrelor versus prasugrel in patients with ACS according to time of hospital presentation remain unknown.

METHODS

This post hoc analysis of the ISAR-REACT 5 trial included 1565 patients with ACS presenting off-hours and 2453 patients presenting on-hours, randomized to ticagrelor or prasugrel. The primary endpoint was a composite of death, myocardial infarction, or stroke; the safety endpoint was Bleeding Academic Research Consortium (BARC) type 3-5 bleeding, both at 12 months.

RESULTS

The primary endpoint occurred in 80 patients (10.4%) in the ticagrelor group and 57 patients (7.3%) in the prasugrel group in patients presenting off-hours (hazard ratio [HR] = 1.45; 95% confidence interval [CI] 1.03-2.03; P = 0.033), and 104 patients (8.5%) in the ticagrelor group and 80 patients (6.7%) in the prasugrel group in patients presenting on-hours (HR = 1.29 [0.97-1.73]; P = 0.085), without significant treatment arm-by-presentation time interaction (P_int = 0.62). BARC type 3 to 5 bleeding occurred in 35 patients (5.1%) in the ticagrelor group and 37 patients (5.3%) in the prasugrel group (P = 0.84) in patients presenting off-hours, and 60 patients (5.9%) in the ticagrelor group and 43 patients (4.6%) in the prasugrel group in patients presenting on-hours (P = 0.17).

CONCLUSIONS

In patients with ACS planned to undergo an invasive treatment strategy, time of presentation (off-hours vs. on-hours) does not interact significantly with the relative efficacy and safety of ticagrelor vs. prasugrel.

CLINICAL TRIAL REGISTRATION

NCT01944800.

Diurnal Variability of Platelet Aggregation in Patients with Myocardial Infarction Treated with Prasugrel and Ticagrelor

Background: Contemporary antiplatelet treatment in acute myocardial infarction (AMI) is based on one of two P2Y12 receptor inhibitors, prasugrel or ticagrelor. The aim of this study was to compare diurnal variability of platelet reactivity between patients receiving prasugrel and ticagrelor during the initial phase of maintenance treatment after AMI. Methods: It was a prospective, two-center, pharmacodynamic, observational study. Blood for platelet testing was sampled at four time points on day four after AMI (8:00, 12:00, 16:00, 20:00). Diurnal variability of platelet reactivity was expressed as a coefficient of variation (CV) of the above-mentioned measurements. Results: 73 invasively-treated patients were enrolled (ticagrelor: n = 47, prasugrel: n = 26). CV was greater in patients treated with ticagrelor compared with prasugrel according to a VASP assay (47.8 [31.6–64.6]% vs. 21.3 [12.9–25.5]%, p < 0.001), while no statistical differences were detected when the CVs of platelet aggregation according to Multiplate were compared between ticagrelor- and prasugrel-treated patients. Ticagrelor-treated patients showed more pronounced platelet inhibition than prasugrel at 16:00 and 20:00 (VASP_16:00: 20.6 ± 15.0 vs. 24.9 ± 12.8 PRI, p = 0.049; VASP_20:00: 18.6 ± 17.7 vs. 26.0 ± 11.7 PRI, p = 0.002). Conclusions: Ticagrelor shows greater diurnal variability in platelet aggregation than prasugrel during the initial maintenance phase of AMI treatment, and this is due to the continuous increase of platelet inhibition after the morning maintenance dose. Both drugs provide an adequate antiplatelet effect early after AMI. Evaluation of the clinical significance of these findings warrants further investigation.

Efficacy and safety of different ticagrelor regimens versus clopidogrel in patients with coronary artery disease: a retrospective multicenter study (SUPERIOR)

Current guidelines favor dual anti-platelet therapy with ticagrelor 90 mg BID (T90BID) over clopidogrel 75 mg QD (C75QD) in addition to aspirin for acute coronary syndrome. However, an increased risk of ticagrelor-related adverse events prompted the evaluation of low-dose regimens. This study (NCT03381742) retrospectively analyzed the data from 11 hospitals on 3,043 patients with coronary artery disease, who received C75QD, T90BID, ticagrelor 45 mg BID (T45BID), or ticagrelor 90 mg QD (T90QD). Compared with C75QD, both T45BID and T90QD showed significantly higher inhibition of platelet aggregation (P < .0001) and lower platelet-fibrin clot strength (P < .0001) induced by adenosine diphosphate. Furthermore, compared with T90BID, two low-dose regimens had a much lower minor bleeding rate and a significantly higher proportion of patients within the therapeutic window for P2Y₁₂ receptor reactivity. There were no significant differences between T45BID and T90QD in the trough plasma concentrations of ticagrelor and its active metabolite. Similar efficacy and safety outcomes were observed in the propensity score-matched analysis. In conclusion, the low-dose ticagrelor regimen, either T45BID or T90QD, may provide a more attractive benefit-risk profile than C75QD or T90BID.